Abstract

In the present work, we have investigated a comparative performance of the silicon (Si) and germanium(Ge)nanoparticles embedded SiO2 floating gate MOSmemory devices. In such devices for low applied fields, the tunneling current is dominated by the direct tunneling mechanism, whereas for higher electric fields, the Fowler–Nordheim tunneling mechanism dominates. As the device dimensions get smaller, problem arises in the conventional MOSmemory devices due to the leakage through the thin tunnel oxide. This leakage can be reduced via charge trapping by embedding nanoparticles in the gate dielectric of such devices. Here one objective is to prevent the leakage due to the direct tunneling mechanism and the other objective is to reduce the write voltage, by lowering the onset voltage of the Fowler–Nordheim tunneling mechanism. Our simulations for the current voltage characteristics covered both the low and the high applied field regions. Simulations showed that both the Si and the Genanoparticles embedded gate dielectrics offer reduction of the leakage current and a significant lowering of the writing or programming onset voltage, compared to the pure SiO2 gate dielectric. In terms of the comparative performance, the Germaniumnanoparticles embedded gate dielectric showed better results compared to the siliconnanoparticles embedded one. The results of the simulations are discussed in the light of recent experimental results.

Received 27 September 2010Accepted 17 January 2011Published online 17 March 2011

Acknowledgments:

One of the authors C.K.S. wishes to thank UGC for Major Research Project. C.K.S. also wishes to acknowledge TWAS support as an Associate to visit UNLP, Argentina to carry out part of the work. One of the authors A.S. wishes to thank DST, Govt. of India for an INSPIRE Fellowship.